I go back and re-read stuff like seiberwing suggested. I also watch the sources of the things they came from. Say your Muse is like Yuki Eiri, so you go back and watch some Gravi or read the manga or watch an AMV or something. I usually get kicked back into the groove by then. It depends; my Muses are all OCs, as I don't really relate to non-OC Muses lol.

P.S. massive love and hugs for you for your newest post, hun. disabled commenting can't stop my loooove